Automated vehicle washing has a history reaching back several decades. In some cases the vehicle to be washed is driven or conveyed through a car wash structure or tunnel while being acted upon by washing elements. In other cases, the vehicle is stationary and the car wash structure includes washing elements that move relative to the vehicle while acting upon the vehicle. In any type of automated vehicle washing system, car wash structures often include washing elements designed to wash particular portions of the vehicles.
One known type of washing element is a cylindrical brush mounted on a shaft and/or hub that rotates about a generally horizontal and longitudinally oriented axis and is usually configured to brush the side surfaces of the vehicle. The horizontal and longitudinally mounted brushes may be arranged in a tunnel conveyor system along with various other brushes including transversely mounted roll-over brushes to clean the top of the vehicle and vertically mounted brushes to clean the front and rear portions. Water and soap are typically applied to the brush cleaning elements and/or to the surface of the vehicle to be cleaned to assist in the cleaning process. The brushes typically engage the generally vertically oriented and longitudinally extending side surfaces of the vehicle along with the generally outward facing surfaces of the wheels, tires and associated hubcaps of the vehicle. Such a brush may, during the course of the cleaning operation, engage a lower panel portion of a longitudinally extending side surface as the vehicle moves past the cylindrical brush.
Typically, two spaced and opposed, generally horizontally oriented and longitudinally extending cylindrical brushes may be employed for washing the lower portion and wheels of both the left (driver) and the right (passenger) sides of the vehicle. Additionally, these horizontal and longitudinally oriented, cylindrical brushes are mounted so that the transverse distance between the cylindrical brushes can be varied, to accommodate vehicles of various widths. The adjustment of the transverse positions of each of the opposed brushes may be provided by a position locator or apparatus (hereinafter referred to as a “position locator”) controlled by a control device of some kind.
While the position locator has positioned a horizontal, rotating, usually cylindrical, brush proximate a vehicle so that the cleaning members of the cylindrical brush may contact and wash the side and wheels of the vehicle, the effectiveness of the washing may be, in part, related to the direction of rotation of the cylindrical brush and the proximity of the cylindrical brush axis to the vehicle side. It has been found that, when washing the driver's side of the vehicle, clockwise rotation of the cylindrical brush (as viewed from the front of the vehicle) provides more effective washing than counter-clockwise rotation of the cylindrical brush. (The opposite is true for the passenger side of the vehicle). This is because the brush members tend to engage the side with an upward motion, which it has been found is advantageous in removing dirt etc. from the surface of the side panel.
However, there are significant problems associated with rotating the brushes in this direction in that during the rotational movement of the cylindrical brush against the side of the car, and the relative upward motion of the individual cleaning elements relative to the side surface, friction between the cleaning members and the lower, rocker panel of the vehicle can tend to draw the cylindrical brush toward the under side of the vehicle. Additionally, it has been recognized that the cleaning members are quite likely to fairly consistently get caught on underside edges and other features that are on or proximate the underside of the vehicle when brushes rotate in this direction. This can cause the rotating brush to experience a significant increase in load and torque and can result in damage to the drive motor for the cylindrical brush.
Accordingly, horizontally and longitudinally oriented brushes adapted for cleaning the side surface of the vehicle are almost always rotated in the opposite direction (i.e., with relative downward motion of the cleaning elements against the side surface of the vehicle). This movement significantly reduces the aforesaid underside movement and catching problems, but impacts significantly upon the quality of the cleaning.
U.S. Pat. No. 4,691,401, issued Sep. 8, 1987 to Machin (hereinafter “Machin”), addresses a recognized problem wherein a vertical, rotating, cylindrical brush may, on occasion, catch in a convergent slot or gap formed by a vehicle bumper and a trailer hitch or coupler. In response to sensing an atypical event, such as, for example, a decrease in rotational motion of the brush, a change in brush orientation, a change in brush torque and/or a change in drive motor current, the rotation direction of the brush is reversed. This system however is not suitable for controlling a relatively continuous tendency of a horizontal, longitudinal brush to be dragged underneath the car resulting in the increasing torque and load on the brush.
One solution to the aforesaid problems in the horizontal and longitudinal oriented brush, is the split brush system, which employ two brushes configured in vertically stacked, side by side relation to each other and which have separate brushes rotating in opposite directions to each other. This solution is however somewhat unsatisfactory and also relatively expensive.